Study data published in the BMJ show that pharmaceutical companies routinely fail to publicly reveal the reasons their drugs are not approved by the FDA. In an analysis of medicines that were rebuffed by the regulator between August 2008 and June 2013, investigators found that press releases issued by drugmakers matched statements about reasons for rejection by the agency only 14 percent of the time. Additionally, study findings suggest companies did not publish press releases for 18 percent of complete response letters issued by the FDA during the study period.

Study researchers assessed all 61 complete response letters issued by the FDA during the study period. The researchers subsequently divided all complete response letters and press releases into discrete statements and determined the degree of concordance between the complete response letters and the related press releases.

The investigators noted that press release statements matched 16 percent of statements on efficacy in the complete response letters, while a match was identified for 15 percent of statements on safety. Moreover, among the 32 complete response letters that cited a need for new clinical studies for safety of efficacy, matching statements were provided in 59 percent of the press releases. In addition, according to the study results, among seven letters from the FDA indicating that mortality rates were higher in treated patients, only one associated press release cited the finding.

"There are substantial differences in content between confidential complete response letters and press releases issued by sponsors," the researchers concluded, adding "the potential benefits of publicly disclosing the agency's detailed rationale for refusing approval include better informing the development of new drugs, facilitating a richer public health discourse and counteracting misconceptions regarding FDA's reasons for denial of applications."